In this interview she conveys the strength of feeling among Brexiters on the Tory benches who will be dismayed if Britain ends up “half in, half out” of the EU.

According to Jenkyns, “Prime Ministers keep their jobs who keep their promises,” and there will be a “catastrophic” loss of faith in the Conservative Party if it breaks its word on Brexit.

ConHome: “Why have you suddenly decided to turn up the volume?”

Jenkyns: “I suppose I’ve been getting frustrated for months really. I wanted to spend more time on the Brexit Committee.

“It’s so imbalanced in favour of the Remainers on there, there are only seven out of 21 who are Brexiters. That was the initial thing, but as we’ve seen in recent weeks with our own colleagues the Remainers seeking to delay or stop Brexit really, and the concessions that were getting made, myself and my colleagues speaking behind closed doors, we were getting incredibly frustrated.

“One of my colleagues had heard from a reliable source that the Government was thinking about extending the Article 50 period, and so there’s myself, Craig Mackinlay and Sammy Wilson, the three of us, all decided look, maybe us backbenchers should put a letter together, to the Prime Minister, and set out what our concerns are, and set out the red lines not only of what the Prime Minister said she was going to honour in her Mansion House speech, but what we feel as Brexiters the public really wanted out of Brexit.

“And so the three of us started putting a letter together, and I suppose it gathered momentum really. We was asking colleagues, we thought about doing a European Research Group one, but we thought not everybody who’s signed the letter is an ERG member…”

ConHome: “You had 33 signatures on there…”

Jenkyns: “We would have had a great deal more. However, some of the colleagues were saying the tone of the letter was rather blunt, rather forthright, and some wanted us to soften it, but they agreed with all the points we wrote on there.

“We would have had about 19 more had we softened the language. But what happened was it got leaked to the Chief Whip. We’d been working on the letter, the three of us, for a whole week without it being leaked. It got leaked to the Chief Whip who spoke to myself and Craig about it, and we said it’s going in anyway.

“But some colleagues then removed their name off the letter. About four colleagues.”

ConHome: “That was a fairly small rate of attrition.”

Jenkyns: “Yes it was, actually. The other thing is as well, we’re trying to do it cross-party, so I spoke to Labour and to the DUP, and it was very close to being all three parties on there, but Labour said to me, and the DUP, after speaking to their colleagues, they want to send their own letters.”

ConHome: “So did Sammy Wilson [a DUP MP] sign it?”

Jenkyns: “Yes, Sammy Wilson did sign it, because it was the three of us together who put it together. So we decided not to publish the names, because we know the ERG letter in February, colleagues on there got told the names wouldn’t be published.

“And we thought you know you’ve got to honour that trust really. Some colleagues wanted the names publishing, some didn’t. We sent texts to colleagues to say that the Chief Whip was aware of it and The Times had contacted us, and so it’s going to be in the weekend papers.

“Feel free if you want your name to be added or speak to the press if you so wish. So we’d let them decide really. But obviously the Prime Minister, when it was delivered, all the names were listed.”

Jenkyns: “The Friday before I sent the letter, all the Brexiters who contacted us, we’ve had a lot, saying please ensure we get the Brexit we voted for, I wanted Brexiters at a roundtable discussion in the constituency.

“Nobody at that meeting said they regret voting Brexit. About 50 per cent was very frustrated, they felt that two years on we’re not necessarily any more forward.

“Why have some of these decisions that we’re waiting for, my constituents are saying to me, not been made before now – we just need to get on with it. That made me realise even more that the letter was right.

“My colleagues and I, Simon Clarke [MP for Middlesbrough South and East Cleveland] was on board by this point as well, and we were getting signatures, but there was a lot of feeling on the backbenches really by Brexiters, that we hoped that the Prime Minister would deliver, we know that her hands were tied, however we just hoped she wouldn’t buckle under the pressure of some of the Cabinet ministers who were very heavily Remain, coming out with unhelpful comments over the past week about Airbus etcetera.

“And that was our feeling really, she’s between a rock and a hard place, she can’t please everybody, the purpose of the letter was to set out there’s more of us Brexiters, and this is what you promised, please deliver.”

ConHome: “So if she doesn’t deliver?”

Jenkyns: “Yeah, absolutely [nervous laughter]. Here we are. There has been meetings going on this week, well telephone meetings, between colleagues, which I’m aware of, backbenchers, where they’re so frustrated.

“We saw the response to the letter in The Times was making out that Brexiters are bullies. I came out on Twitter and said, why was that rhetoric not used against the Remainers?

“The previous week we hadn’t voted against the Government but the Remainers had. We were just merely putting our thoughts in a letter. But there’s still a lot of frustration at the moment. We’re all sat on our hands at the moment because we want to see what Friday brings.

“We just really hope the Brexiters in the Cabinet, they really fly that flag. It’s going to be far more catastrophic for the party if we don’t deliver Brexit.

“Like we know the Norway model’s been put out there, whereby we’re still paying a hell of a lot of money in, but we don’t necessarily have a seat at the table.”

ConHome: “So it could be worse than being in?”

Jenkyns: “Completely. Actually my team found in Hansard copies of the Prime Minister clearly stating in December it wouldn’t actually be a Brexit if we went with the Norway model.

“We’ve got to not be short-termist about this. Because if we don’t deliver Brexit, if we’re half in and half out, it’s going to be catastrophic for the Conservative Party.

“They’re not going to trust the party. In our manifesto, all of us, Brexiters and Remainers, we stood on that manifesto that we would deliver Brexit.

“If we don’t deliver and we’re still tied to the EU, we still have the freedom of movement, we’re still tied in some kind of trading bloc where we can’t do free trade agreements elsewhere, the public will vote as they see fit, and that’s a big concern to me really, because I feel they’ll feel let down and we could lose votes as a result of this.”

ConHome: “So do you think the Prime Minister would survive such a Norway-style concession?”

Jenkyns: “Well to be honest, like I said recently, in my statement that I put out there, and the Telegraph did a follow-up, this isn’t a threat, it’s just as history shows, Prime Ministers keep their jobs if they keep their promises.”

ConHome: “So she’s got to keep her promises. What about the Brexiters in Cabinet if she made Norway-style concessions? Should they then resign?

Jenkyns: “Well I can’t speak for them, but I hope that they will fight that and not allow it to happen. The concern is it could be packaged up as not the Norway option but there might be just one thing slightly different, you know, and it’s called the British option.”

ConHome: “But it’s effectively Norway.”

Jenkyns: “Yes. So that is our concern as Brexiters. The Prime Minister said what, there’s 159 people to oust her, none of us are trying to oust her, we just want her to honour her commitment and her promises. And you know, it isn’t 159 people. We’ve got a minority government.

“I’m not going to let my constituents down. I will keep fighting for my constituents.

“I really do hope and pray the Prime Minister delivers. She just needs to be strong with her Cabinet ministers, and not necessarily lead by consensus.”

ConHome: “Were the Prime Minister to go, who as leader would go down well in your sort of seat in Yorkshire, do you think?”

Jenkyns: “I’m not sure yet. If it was prior to us fully pulling out of the EU then it’d be a different person than afterwards. It opens up the field. At the moment it’s all about Brexit.

“Once Brexit is sorted, and we’re in that good place where can move forwards as a country and as a party, then I think it opens up other possibilities of who we could choose. We’re hoping it’s after the Brexit process.”

ConHome: “Has this been very tough for you personally? Have you felt under a lot of pressure?”

Jenkyns: “I have to say I’m a northerner. I saw in my family life, fantastic parents, Dad’s business doing well, and then his business went bankrupt, and us living in a council house, and us hiding behind the sofa when they’re going to cut the electric off.

“So I’ve seen both sides of life, and it just makes you a lot tougher, and probably fight for what you believe in more.

“In politics, people come and go, including ourselves really. Nothing’s forever. Let’s try and follow our heart and do what we think’s right. If I was a career politician, I wouldn’t have resigned as a PPS.”

ConHome: “So you don’t think of yourself as a career politician?”

Jenkyns: “No, no, I call myself an accidental politician really. I want to be able to sleep at night.

“I suppose the final thing is that we hope the PM delivers. We’re all rooting for her to deliver. We’re not trying to be the awkward squad.

“I think we’ve not played our cards strong enough, to be honest with you. The EU believes that we are giving the money prior to everything being settled. Now that’s not a good negotiating position.

“About three weeks ago, I asked the Prime Minister if we are preparing for a no deal, because that is a strong card. We’ve got to be tough and bold.

“When Guy Verhofstadt appeared before the Brexit committee, I asked him what is the EU prepared to give, or give up, or compromise on with the UK? Nothing, he said.

“If we’re soft with them, they are not going to move an inch. So we need to be bold.”